Carbonaceous chondrite
From NewMarsWiki
A carbonaceous chondrite or a C-type chondrite is a type of chondritic meteorite which contains high levels of water and organic compounds, representing only a small proportion (~5%) of known meteorites. Their bulk composition is mainly silicates, oxides and sulfides, whilst the minerals olivine and serpentine are characteristic. The presence of volatile organic chemicals and water indicates that they have not undergone significant heating (>200°C) since they formed, so their composition is considered to be representative of the solar nebula from which the solar system condensed.